Dopant-induced electron localization drives CO 2 reduction to C 2 hydrocarbons

The electrochemical reduction of CO to multi-carbon products has attracted much attention because it provides an avenue to the synthesis of value-added carbon-based fuels and feedstocks using renewable electricity. Unfortunately, the efficiency of CO conversion to C products remains below that necessary for its implementation at scale. Modifying the local electronic structure of copper with positive valence sites has been predicted to boost conversion to C products. Here, we use boron to tune the ratio of Cu to Cu active sites and improve both stability and C -product generation. Simulations show that the ability to tune the average oxidation state of copper enables control over CO adsorption and dimerization, and makes it possible to implement a preference for the electrosynthesis of C products. We report experimentally a C Faradaic efficiency of 79 ± 2% on boron-doped copper catalysts and further show that boron doping leads to catalysts that are stable for in excess of ~40 hours while electrochemically reducing CO to multi-carbon hydrocarbons.